1. Runway Weather Information Systems & Grip
FPAW, Las Vegas
Paul Bridge, November 2015

2. RWIS – Runway Weather Information System
Surface Temperature
Surface State
Freeze Point
Chemical presence & amount
Black Ice
11/15/2018
[Name]

3. Non-invasive pavement sensors
Measure:
Pavement Temperature
Pavement State (dry, moist, wet, frost/snow, ice
Layer thickness of above
Grip
11/15/2018
[Name]

4. Grip – measuring slipperiness
0.8
0.7
0.6
0.4
0.1
This is what DOT folk have learnt from years of observing the grip readings…….
Above .6 mobility is good
.5 to .6 slush or ice forming
.4 to .5 snow pack or icy
Below .4 cars may start sliding off
.3 and lower multiple slide offs possible; mobility greatly affected
DSC111 measures independently
Snow/Frost (crystalline ice)
Ice
Water
Different combinations have been correlated to actual friction conditions
A single index is output which is termed GRIP
A simple way of expressing all that complexity with one number
TALPA– Take-off and Landing Performance Assessment ?

5. Lost Trail Pass, Idaho : Guess the driving (landing
Lost Trail Pass, Idaho : Guess the driving (landing!) conditions on the following days?

6. Did you get them right? The weather sensors did!
Air Temp: 25ºF
Road Temp: 30ºF
Road State: Slush
Grip: Good
Air Temp: 25ºF
Road Temp: 50ºF
Road State: Dry
Grip: Excellent
Air Temp: 28ºF
Road Temp: 43ºF
Road State: Wet
Grip: Good
Air Temp: 20ºF
Road Temp: 28ºF
Road State: Ice
Grip: Poor
Air Temp: 23ºF
Road Temp: 43ºF
Road State: wet
Grip: Good
Air Temp: 24ºF
Road Temp: 28ºF
Road State: Ice
Grip: Very poor
Air Temp: 23ºF
Road Temp: 28ºF
Road State: Ice
Grip: Poor
Air Temp: 14ºF
Road Temp: 21ºF
Road State: Dry
Grip: Excellent
Air Temp: 36ºF
Road Temp: 39ºF
Road State: Dry
Grip: Excellent
Salt Residue
Salt Residue

7. How can Non-intrusive sensors be used at airports?
11/15/2018
[Name]

8. DSP310 Components Viewing Data Over the Internet Vaisala Database
Smart Phone In-vehicle Display
Air Temperature
Dew Point
Pavement Temperature
Surface Condition
Friction/Grip
Layer Thickness
Interface Unit

9. How Does Non-intrusive Sensor compare with ‘regular’ friction testing systems?
Index of grip, is scaled to the value of friction of a typical road surface and a car tire
Tests with FINRA using a decelometer in all types of slippery conditions
RMS error in friction units is 0.07
Nuebert Aero Corp tested DSC111 with trailer based friction system – results unknown
11/15/2018
[Name]

10. Integrated into RoadDSS Navigator

11. Grip Forecasts
Planning made easy by introducing a call to action level of grip
Clear period of concern from forecasts of Grip
Observed Grip
Forecast Grip
Call to action level of Grip
Action needed
Multiple weather reasons for a slippery road condensed into one Grip reading

12. Grip based winter maintenance/operations system
Remote sensing network
Maintenance program
Action Planning based on grip forecast
Quality control
Continuous improvement
Real time logging of actions
Reporting
Performance monitoring
Grip forecasts

13. Thank You